There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

计量经济分析 = Econometric analysis

This chapter discusses leading problems linked to energy that the world is now confronting and to propose some ideas concerning possible solutions. Oil deserves special attention among all energy sources. Since the beginning of 1981, it has merely been continuing and enhancing the downward movement in consumption and prices caused by excessive rises, especially for light crudes such as those from Africa, and the slowing down of worldwide economic growth. Densely-populated oil-producing countries need to produce to live, to pay for their food and their equipment. If the economic growth of the industrialized countries were to be 4%, even if investment in the rational use of energy were pushed to the limit and the development of nonpetroleum energy sources were also pursued actively, it would be extremely difficult to prevent a sharp rise in prices. It is evident that it is absolutely necessary to pursue actively the development of coal, natural gas, and nuclear power if a physical shortage of energy is not to block economic growth.

World energy outlook

Introduction to stochastic programming

This paper applies logistic regression to network fault statistics and geographic information. The logistic regression model is further processed in order to obtain raster formatted fault rate surfaces that aid network planning, e.g., in automated routines or as background maps. The fault rate surfaces are applied as a part of an automated network planning routine planning case based on real network data from the same distribution system operator as the fault data. The results can help in the planning of more reliable, yet economically feasible, power distribution networks.

Generating fault rate surfaces using network fault statistics and geographic information

This paper presents a new and efficient formulation for the state estimation (SE) which can be solved in one single shot of computation. The proposed approach adopts line flows and the square of voltage magnitudes as the problem state variable and considers both active and reactive power quantities. The objective function is to minimize the weighted sum of the least square values of measurement residuals. The nonlinearity associated with line losses is left by assuming these values as slack variables. Numerical studies are conducted through two standard networks. In order to compare the performance of the proposed method, the conventional weighted least square (WLS) state estimation with Gauss-Newton AC power flow is also accommodated. Simulation results demonstrate that the proposed method outperforms the conventional one particularly from the speed while keeping the accuracy in a reasonable range.

A new approach for AC state estimation based on a linear network model

Protection of Lightning Disturbances on MV Underground Cable

High-Frequency Current Sensor for Power Network On-line Measurements

Emergence of reformation and privatization in energy systems has caused the development of multi-agent distribution systems. In this context, each agent as an independent entity aims to efficiently operate its respective resources; while, the distribution network operator (DNO) strives to control the grid in an efficient and reliable manner. Respectively, in case of failure incidences in the grid, DNO should address the economic losses as well as reliability concerns of the agents. Consequently, this paper intends to organize a framework that enables the DNO in order to incentivize the cooperation of agents to alleviate operational effects of the contingency condition. Accordingly, DNO provides bonuses to agents to modify their scheduling with the aim of optimizing the incurred operating costs in post-contingency conditions. Respectively, Stackelberg game is applied to model the incentivizing resource scheduling optimization in post-contingency conditions, and strong duality condition is used to re-cast the preliminary bi-level model into a one-level mathematical problem. Furthermore, a step-wise strategy is illustrated to facilitate the application of the obtained optimization model while considering islanded areas in the grid. Eventually, the proposed strategy is implemented on the IEEE-33-bus-test-network to examine its usefulness and applicability in management of the distribution networks in post-contingency conditions. 

Matti Lehtonen

Papers

Generating fault rate surfaces using network fault statistics and geographic information

A new approach for AC state estimation based on a linear network model

Protection of Lightning Disturbances on MV Underground Cable

High-Frequency Current Sensor for Power Network On-line Measurements

Optimal energy management of distribution networks in post-contingency conditions